Ignore duplicated event CompleteLogin from UI

chrome/browser/chromeos/login/existing_user_controller.cc

Index: chrome/browser/chromeos/login/existing_user_controller.cc
diff --git a/chrome/browser/chromeos/login/existing_user_controller.cc b/chrome/browser/chromeos/login/existing_user_controller.cc
index 837d5fae579d478cb9c16f7aff6cc1ce25367ce9..7d4fe779846155910a7e2cc596b21168080a6a47 100644
--- a/chrome/browser/chromeos/login/existing_user_controller.cc
+++ b/chrome/browser/chromeos/login/existing_user_controller.cc
@@ -305,6 +305,10 @@ void ExistingUserController::SetDisplayEmail(const std::string& email) {
 
 void ExistingUserController::CompleteLogin(const std::string& username,
                                            const std::string& password) {
+  if (!host_) {
+    // Complete login event was generated already from UI. Ignore notification.
+    return;
+  }
   if (!time_init_.is_null()) {
     base::TimeDelta delta = base::Time::Now() - time_init_;
     UMA_HISTOGRAM_MEDIUM_TIMES("Login.PromptToCompleteLoginTime", delta);